Flexible sealing joint



Dec. 30, 1947. J. M. CROM FLEXIBLE SEALING JOINT Filed June 1, 1944 5 wM A, My 1 Patented Dec. 30, 1947 UNITED STATES PATENT OFFICE FLEXIBLESEALING JOINT John M. Crom, Washington, D. C.

Application June 1, 1944, Serial No. 538,272

Claims. 1

This invention relates to concrete structures embodying a vertical wallsupported on a base and relatively displaced therefrom due to settingshrinkage and/or compression from stressed steel reinforcement appliedto the wall, and the primary object of the invention resides in theprovision of resilient means between the wall and base for supportingthe former on thelatte providing a liquid tight seal therebetween at thejoint and permitting relative shifting movement of the wall toaccommodate the said displacement.

My Patent 2,342,181 discloses a concerte tank and illustrates inwardshrinkage of the wall relative to the base as the concrete sets. Also inmy Patent 2,315,894 is illustrated a concrete tank in which the wall isplaced and held in compression by stressed steel reinforcement extendingcircumferentially around the wall. Such compression causes a furtherinward shifting of the wall relative to the base. The wall rests on butis a unit separate from the base and in my Patent 2.342181 steelreinforcement is provided for permitting the shrinkage displacement andmaintaining the wall in tight contact with the base. The inventiondisclosed in this application provides a supporting layer of flexiblematerial between the wall and base for accommodating the walldisplacement and maintaining a tight liquid seal at the joint.

The flexible material employed at the wallbase joint will be ofsubstantial vertical thickness, have sufficient resiliency to permit thewall displacement and will be of a compressible nature adapting it toform a tight seal with the cooperating base and wall surfaces. Rubber,and particularly certain synthetic rubbers of the types hereinafterdescribed, are preferred for the flexible material employed and, whilethe same in a relatively firm form can be employed as the sole elementfor performing the functions stated, Imay in some cases desire tocombine therewith, and preferably molded thereinto, a plurality of solidsupporting members such as steel rockers for taking the weight load andlimiting downward movement of the wall relative to the base. Theproduction of an improved and flexible sealing joint of this nature andfor the purposes described comprises a further object of this invention.

These and other features of the invention will be best understood andappreciated from the following description of preferred embodimentsthereof selected for purposes of illustration and shown in theaccompanying drawings in which,

Fig. 1 is a fragmentary view of a concrete tank employing my invention,

Fig. 2 is a fragmentary sectional plan view of a sealing unit that canbe employed therein,

Fig. 3 is a fragmentary elevation of a modified 2 construction, partlybroken away along line 33 of Fig. 4,

Fig. 4 is a sectional view taken on line 4-4 of Fig. 3, and 5 Fig. 5 isan enlarged view of a portion of Fig. 4.

My invention is particularly applicable to use in concrete tanksembodying a vertical wall supported on a concrete base. A tank of thisnature comprises a vertical wall In on a concrete base I2 as illustratedin Fig. 1. The wall comprises a main inner body portion l4, stressedsteel reinforcement 15 extending circumferentially around and holdingsuch portion in compression, and an outer cover portion 18 bonded to andprotecting the reinforcement and inner body. The reinforcement I6 ispreferably steel wire of high tensile strength and is wrapped tightly onand around the wall portion l4 after the latter has fully set, in themanner described in my Patent No. 2,370,780.

The wall l4 shrinks inwardly during setting of the same, as illustratedand described in my Patent 2,342,181, and the wrapping of the steelreinforcement l6 thereunto under high tensile stress places the wall incompression and causes it to shift further inwardly relative to thebase. Because of this shifting of the wall on the base, the wall andbase must not only be constructed asindependent units but mustfurthermore be so constructed that the wall is permitted thisdisplacement without disrupting either unit or causing leakage at theirjunction. The novel construction of my invention as herein disclosed isparticularly adapted to serve these functions with great facility.

As illustrated in Fig. 1, a layer 20 of flexible material ofsubstantiall thickness is built into the structure between the wall andbase units. The layer is continuous and can be a unit or it can beconstructed and placed in sections as illustrated in Fig. 2, thesections being joined together by suitable joints as indicated at 22 and24. The material will necessarily be relatively firm, flexible and of aresilient and somewhat compressible nature adapted to form a tightliquid seal under pressure engagement with the adjacent faces of thewall and base. The most suitable material serving these functions whichI have so far determined comprises rubber and more particularly certainsynthetic rubbers.

Neoprene compound M-2617, manufactured by the United States RubberCompany and having a durometer of approximately 70, plus or minus five,appears to be quite satisfactory, and Thiokol and other less expensivesynthetic rubbers of like durometer are also well adapted to this use.The greatest displacement of the wall takes place during the preliminarysetting of the concrete and the compression banding of the wall, thoughcontinued displacement does take place for a period of three to sixmonths 3 after which the wall becomes substantially settled to permanentposition. When the wall has become thus settled the joint materialcontinues to serve 'its' sealing function and maintain a tight leakproofjoint between the wall and base.

The functions to be served by the layer or block of material 20 are (1)the forming of a tight sealing joint between the wall and base and (2)the permitting of shrinkage movement of the wall relative to the basewhile maintaining the sealing joint intact. These functions areperformed with maximum facility in accordance with my invention in whichthe block 20 is of a width or thickness substantially coextensive withthe thickness of the wall horizontally, whereby not only providing asolid block of substantial mass for supporting the heavy weight of thewall but also providing sealing contacts over wide areas of the wall andbase. The substantial area of sealing contacts thus provided throughoutthe thickness of the wall serves to maintain a tight seal at the jointeven though portions of the sealing contacts with the wall and baseshould become loosened or defective, and the large mass of materialserves to support the wall without undue crushing effect on thematerial.

It may in some cases be desirable to limit the settling or approachingmovement of the wall relative to the base and in Figs. 3-5 I haveillustrated a modified structure for serving this function. In this casethe joint material 26 may have molded thereinto a. plurality of solidmembers in the form of steel rockers 28. These rockers can be of theshape illustrated in Fig. 5, each having arcuately shaped top and bottomsupporting surfaces 30 and 32 and intermediate V- shaped recesses 34 forreceiving the joint material molded into supporting contact therewith.The rockers are placed in spaced relation with their arcuate surfacesdirected radially, and preferably steel plates 36 and 38 are providedadjacent to the wall and base for contact with the rockers whereby tosustain the load without danger of crushing the concrete. The plateswill also preferably be of a width less than the thickness of the wallwhereby the joint material 26 will make direct sealing contact with thewall and base at both sides of the plates. The vertical thickness of thejoint material will ordinarily approximate one to two inches and therockers will be of a diameter approximately it less whereby permittingthe material to compress 1A3" before the load is taken by the rockers,although these dimensions can be varied as experience and conditionsrequire. The dimensions will however in any case be such that the walland base are brought into firm sealing contact with the sealing materialand it will continue to maintain such contact. It will be apparent thatthe limiting of the crushing load eff ct on the sealing materialeliminates the dange of unduly compressing the material to a degre whereit might lose a substantial portion of its esiliency and sealingeffectiveness.

It will now be apparent that I have produced a new and improved flexiblesealing joint for concrete construction and a method of constructingconcrete tanks and the like with provision for the wall displacementwhich results from shrinkage and compression while at the same timeproviding and maintaining a tight liquid seal at the junction of thewall and base.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent of the United States is:

1. A tank comprising a concrete base, a horizontally endless verticalwall Lsupported on andextending upwardly from the base, and a continuouslayer of flexible and liquid impervious material of substantialthickness vertically between the wall and base and supporting the wallin spaced relation on and above the base, said material being of athickness horizontally substantially commensurate with the thickness ofthe wall and being in sealing contact with the wall and base over areassubstantially commensurate with the area of the bottom face of the walland providing a leakproof Joint between the wall and base and itsflexibility permitting a substantial lateral movement of the wallrelative to the base without relative sliding movement between thematerial and the wall or base.

2. The combination defined in claim 1 in which said material comprises asynthetic rubber of a durometer approximating '70 plus or minus five.

3. In combination, a concrete base, a concrete wall supported on andextending upwardly therefrom, a continuous layer of flexible material ofsubstantial thickness vertically between the wall and base, and aplurality of solid elements in and spaced along said layer andcooperating with said material to support the wall on the base, saidmaterial being in tight face to face pressure sealing contact with thewall and base continuously along the entire length of the Wall and itsflexibility permitting a substantial lateral movement of the wallrelative to the base without sliding movement of the material relativeto the wall or base. and said solid elements positively limitingmovement of the wall toward the base.

4. The combination defined in claim 3 plus plates of steel or the likedisposed between said elements and the wall and base for distributingthe weight load over the wall and base areas.

5. A tank comprising a concrete base, a horizontally endless verticalwall supported on and extending upwardly from the base. a continuouslayer of flexible material of substantial thickness vertically betweenthe wall and base, and a plurality of steel rockers in and spaced alongsaid layer in a position to rock radially of the tank, said rockerscooperating with said material to support the wall and said materialbeing in tight face to face pressure sealing contact with the wall andbase continuously along the entire length of the wall and itsflexibility permitting a substantial lateral movement of the wallrelative to the base without sliding movement of the material relativeto the wall or base.

JOHN M. CROM.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,129,932 Huddleston Sept. 13,1938 FOREIGN PATENTS Number Country Date 16,877 Great Britain July 30,1896 170,528 Switzerland 1934 OTHER REFERENCES Engineering News-Recordfor January 28, 1943, Navy builds prestressed concrete tanks, pages 5'7,58 and 59.

